One known refrigerant evaporator for use in a refrigeration cycle of a vehicle air conditioner includes many refrigerant tubes that have refrigerant flow channels through which a refrigerant flows in a vertical direction, that are arranged in parallel in a direction perpendicular to a flow direction of air flowing outside the refrigerant flow channels, and that are arranged in a plurality of rows from front to rear in the flow direction of the air; and a pair of upper and lower tanks for distributing or collecting the refrigerant, disposed in the direction perpendicular to the flow direction of the air and connected to top ends and bottom ends, respectively, of the many refrigerant tubes, each tank having a partition wall partitioning the interior thereof into a first tank portion and a second tank portion that correspond to the plurality of rows of the refrigerant tubes in a row direction. The refrigerant evaporator is configured such that the refrigerant, flowing in through a refrigerant inlet, flows sequentially into the refrigerant tubes in a plurality of blocks partitioned by partition plates disposed at a plurality of positions in the tanks to undergo heat exchange with the air, thereby cooling the air.
Patent Document 1 discloses a refrigerant evaporator having the above configuration in which one of the plurality of blocks is a U-turn block where the refrigerant flows into the first tank portion of the upper tank in a direction along the partition wall, flows from the first tank portion into the second tank portion through a side refrigerant channel, and is distributed and flows from the first and second tank portions into the plurality of refrigerant tubes. Patent Document 2 discloses a refrigerant evaporator in which a plurality of communication holes are provided in the partition wall so that the refrigerant collected in the second tank portion of the upper tank through the plurality of refrigerant tubes flows directly into the first tank portion on the opposite side of the partition wall.
Patent Document 1:
Publication of Japanese Patent No. 3637314
Patent Document 2:
Japanese Unexamined Patent Application, Publication No. 2001-74388